Method of preparing a quaternary ammonium compound



atent Free Patented Mar. 19, 1963 3,082,227 METHGD OF PREPARHNG A QUATERWARY AMMONIUM COMPGUND Allan E. Short, Norwalk, Comm, assignor to American Cyanarnid Company, New York, N .Y., a corporation of Maine No Drawing. Filed Sept. 27, 1961, Ser. No. 140,993

7 Claims. (Cl. 260-4045) This invention rel-ates to a method of preparing a quaternary ammonium compound and, more particularly, a quaternary ammonium compound represented by the general formula In the above formula R is a member of the group consisting of aliphatic and alicyclic radicals containing at least 7 carbon atoms, R and R" are members of the group consisting of alkyl radicals having from 1 to 3 carbon atoms, inclusive, and rnonohydroxyalkyl radicals having from 2 to 3 carbon atoms, inclusive, R is a monohydroxyalkyl radical having from 2 to 3 carbon atoms, inclusive, and Y is the anion of an acid.

Illustrative examples of radicals represented by R in Formula I are heptyl, octy-l, nonyl, decyl, undecyl, tridecyl, hept-adecyl, the residue of abietic acid, etc.; illustrative examples of radicals represented by R and R" are methyl, ethyl, propyl, isopropyl, hydroxyethyl, hydroxypropyl, hydroxyisopropyl, etc; illustrative examples of radicals represented by R' are hydroxyethyl, hydroxy propyl and hydroxyisopropyl; illustrative examples of anions represented by Y are the halide ions (that is, Y can represent halogen, more particularly chlorine, bromine, fluorine or iodine), sulfate, sulfonate, phosphate, borate, cyanide, carbonate, hydrocarbonate, thiocyanate, thiosulfate, isocyanate, sulfite, bisulfite, nitrate, nitrite, oxalate, silicate, sulfide, cyanate, acetate and the other common inorganic anions.

Quaternary ammonium compounds of the kind prepared by the method of this invention are claimed, both broadly and specifically, as new compounds in Cook and Moss US. Patent No. 2,589,674 dated March 18, 1952.

With further reference to the definition of R and as stated in the aforementioned Cook et al. Patent 2,589,674, R may be any aliphatic or alicyclic radical containing a sufiicient number of carbon atoms to provide Ia hydrophobic radical which will provide orientation of the compounds at an oil-water surface. Thus, R can be a radical derived from a wide variety of monocarboxylic acids including caproic, decenoic, lauric, myristic, palmitic, stearic, arachidic, oleic, and other more highly unsaturated fatty acids having from 14 to 18 carbon atoms and which are obtained from vegetable and animal oils and fats, e.g., soyabean oil, cottonseed oil, coconut oil, linseed oil, castor oil, dehydrated castor oil and the like, or from other commercial sources such as tall oil. Additionally, R can be a radical derived from an alicyclic monocarboxylic acid including petroleum naphthenic acids of 7-14 carbon atoms having boiling points within the range of 215310 C., as described in Ellis Chemistry of Petroleum Derivatives, (1934 edition), pages 10624082, or abietic acid and the like.

The number of carbon atoms in the aliphatic or alicyclic radical represented by R is largely dependent upon the particular use to which the quaternized compound is to be placed. Thus, for some uses of the compound it may be desirable that R represented a radical containing in excess of 20 carbon atoms. However, for most wetting, emulsifying, antistatic and similar uses, it is generally more desirable that R represent a radical containing not more than about 20 carbon atoms and preferably, for most ready dispersibility in aqueous media, not more than 19 carbon atoms.

One of the important and rapidly growing uses of quaternary ammonium compounds of the kind embraced by Formula I is as an antistatic agent, e.g., as a component of or in the surface treatment of various plastic and textile materials. Examples of such materials are those comprised or consisting essentially of polyvinyl chloride, polystyrene, poly-(rnethyl methacrylate), polyethylene, polypropylene, copolymers of vinyl chloride and vinyl acetate, and the like. Examples of textile materials to which the aforesaid antistatic agents can be applied are those composed of or containing fibers or filaments of wool, silk, cellulose esters (e.g., cellulose formate, cellulose acetate, cellulose propionate, cellulose butyrate, etc), cellulose ethers (e.g., ethyl cellulose, benzyl cellulose etc.), viscose rayons, nylon, polyesters, vinyl resins (-e.g., vinyl chloride polymers and copolymers, acrylonitrile polymers and copolymers, etc), polypropylene, and other natural and synthetic textiles in the form of continuous-filament yarn, staple fiber, tow, roving, knitted, woven or felted fabrics, or in other form.

Prior to the present invention the common method of preparing quaternary compounds embraced by Formula I has been to effect the reaction between the aliphaticor alicyclic-amidopropyl amine and an alkylene oxide, e.g., ethylene oxide, in an aqueous or aqueous ethanol solution, the latter being usually a 50-60 mixture by volume of water and alcohol. An acid is added to the solution, the anion of which corresponds to the anion represented by Y in Formula I, either prior to, during or after the addition of the alkylene oxide.

The foregoing method of preparation has several disadvantages. For example, if the reaction is carried out in water, the reaction does not proceed with optimum etficiency and lower yields of product are obtained. Furthermore, when the reaction is carried out in 100% water or in a liquid reaction medium comprising Water and an organic solvent, there is the additional time and expense incurred in drying the quaternary compound if one Wants to market a dried product.

The present invention is based on my discovery that optimum yields of product can be obtained and the foregoing diificulties can be obviated by carrying out the reaction between the aliphaticor alicyclic-amido-propyl amine in a liquid reaction medium of a limited class or group and which is critical in practicing the present invention. More particularly, the liquid reaction medium used in carrying the instant invention into effect consists essentially of at least one member of the group consisting of dioxane, ethylene glycol, ethylene glycol monoethyl ether, acetone and chloroform. The reaction medium is essentially anhydrous and, depending upon the acid used, may be almost completely anhydrous. In any case, only such water is added to the reaction mixture as may be present in the concentrated acid employed or in the commercially available solvent of the kind used in practicing this invention.

The foregoing results were all the more surprising and unobvious when it is considered that they were obtained without adversely affecting the useful properties of the quaternary ammonium compound, more particularly as an antistatic agent. For example, when gamma-stearamidopropyl dimethyl beta'-hydroxyethyl ammonium nitrate was made using ethylene glycol as the liquid reaction medium and then was tested as an antistatic agent as described more fully hereinafter, the

,ethylene glycol monoethyl ether, ethylene glycol, acetonitrile, acetone and chloroform in the individual example) and 100 g. (0.272 mole) of gamma-stearamidopropyl dimethyl amine are placed in an autoclave. The temperaantistatic value (electrostatic locator reading determined ture is raised to 75-80" C. with accompanying increase as hereafter described) was between 1.5 and 0. In in pressure ranging from 6-30 p.s.1., and ethylene oxide marked contrast, when the same compound made using -g., 0.34 mole) is added over a period of from 2 to absolute ethyl alcohol as a liquid reaction medium was 6 hours. Upon completion of the ethylene oxlde addisimilarly prepared and tested, the antistatic value was tion, the reaction mass is cooled. Its pH ranges be-:

60. It may here be mentioned that an electrostatic 10 tween 9.2 and 10.8 in the individual case. Concentrated locator reading of from 0 through 10 is generally con- (70%) nitric acid is added to lower the pH to between sidered to indicate static-free conditions; a value of 5.6 and 7.8 in the individual example, the amount of from 11 through 100 indicates no static control; while 70% HNO required to do this rangmg between 10 and a value over 100 indicates no static control. From this g. The results are summarized in Table I.

TABLE I Approximate Theoretical Amount Ex. 70% pH after No. Solvent Reaction pH at HNO; ac1d Yield Remarks time end of added addition of pro- Water. Solvent.

(hrs.) reaction g.) duct. perceutperccnt percent 1 Dioxane 2 10.6 25 5.9 30.0 2.2 58.8 Productisahcavy,viscousliquid. Solvent I23%1;0VllldgaVB a waxy solid containingl 501 S. 2 Ethylene glycol monoethyl 2% 2 24 5.85 38.8 2.1 59.1 Prodl ict dark brown, quite fluid liquid.

6 G 3 Ethylne glycol 1% 9.2 23 5.6 38.8 2.4 58.8 *K2a5rl7 Figchcr determination indicates 4 Acetonitrile 4 10 7.8 36.3 0.9 62.8 Pale, yellow solid precipitated after addition 0510 2. acid. pH lowered to 5.4 with cone. HNO; before use.

5 Acetone 3 10.8 24 5. 8 38.9 2.1 59.0 Most of solvent had evaporated in 2 days.

6 Chloroform 4 9.6 23 5.7 38.8 2.0 50.2 Clear. reddish brown solution.

it will be seen the differences between an antistatic EXAMPLE 7 ratmg of e 60 {nerdy .dlfierences m A 0.05% (solids basis) aqueous solution, using de-' gif g g a i i g g g g s. 22 1 ionized water, is made of each of the quaternary com-' thosevskinednin 2 y as pre m y pounds of Examples 1 through 6, adding HNO when In General the uatmar ammon.um Ound necessary, to ad ust the pH to within the range of about braceg b i i I M are d zg g 4.5 to 6.0. A woven cloth of polyacrylonitrile fibers is the methgds reviousl 3 the th 40 dipped into the solution, excess treating agent is removed 1 1 e c p by squeezing between two rollers, and the resulting imtion that a different liquid reaction medium is employed. r a t d 1 th d d F f 5 For more detailed information on the prior-art techp 6 C0 18 He m an Oven at or mmlie see the aforementioned Cook et a1 U 8 Patent utes. The dried, treated polyacrylonitrile cloth is rubbed 3 589 67 4 and also Patent No 2 5 dated against a woolen cloth, then held to aSimco Electrostatic Locator, and a reading is recorded. The average of at 2 32 2 2? s m gg g ggf made m least five such readings is taken as a measure of the anti- Practicing the present invent'ion the reaction static rating of the individual specimen of polyacrylonip trile cloth. The electrostatic readings are taken under tween the ahphtlchor ahcychc'amldopmpyl amme i substantially the same temperature and humidity condithe alkylene oxide is effected at a temperature ranging tions and in nearly all cases on the same y from about 35 C. up to the boiling temperature of the The inter retatio ofr adn m h h1 r m reaction mass or at higher temperatures under super- 11 throughploo i i fi g g 25 g f g atmospheric pressure, e.g., up to about 200 C. As herefore The result T M H g inbefore stated, the acid corresponding to the salt of the S are glven m a e quaternary ammonium compound can be added either TABLE 11 prior to, during or after the addition of the ethylene oxlde. throughout. an of such i as deslred as Antistatic evaluation of quaternary Approx. pH Electrostatic conditions may require. The reaction between the am1doammonium compound of example of treating locator propyl amine reactant and the alkylene oxide can be Ieadlng partly or wholly completed in the presence or absence of an acid. However, if insufficient or no acid has been "1113 5 added to the liquid reaction medium prior to the time -5-0 when the addition of the alkylene oxide has been com- 21% 2 pleted, then the required amount of acid to form the salt is added after completing the addition of the alkylene oxide.

In order that those skilled in the art may better understand how the present invention can be carried into effect the following examples are given by way of illustration and not by way of limitation.

EXAMPLES l-6 Preparation of Gamma-Stearamidopropyl Dimethyl Beta-Hydroxyethyl Ammonium Nitrate In these examples 200 g. of the solvent (dioxane,

In each case the reading varied from the higher value given to 0 in a few seconds.

EXAMPLES 81 1 These examples illustrate the preparation of gammastearamidopropyl dimethyl beta-hydroxyethyl ammonium nitrate using, as the liquid reaction medium, representative solvents that yield a product having an unsatisfactory antistatic rating, viz., absolute ethyl alcohol, ben zene, carbon tetrachloride and heptane. The results are summarized in Table III.

TABLE III Approximate Theoretical Amount Ex. 70% pH after N0. Solvent Reaction pH at HNO; acid Yield Remarks time end of added addition of mod Water, Solvent. (hrs) reaction (g.) uct. percent percent percent 8 Absolute ethyl alcohol 3 9.1 25 5.7 39 2.2 58.8 Clear tannish solution obtained. After 2 weeks standing. mixture had pH of 4.8. 9 Benzene 6 10.1 23 5.7 38. 8 2.0 59.2 Material separated into a clear,uppcr layer and an orange-brown lower layer. l- Carbon tetrachloride 4 9. 2 6 7.0 37.0 0.6 62. 4 Light brown solid began to form after addition of 6 m1. HN03. 11 Heptane 4 10.0 21 6.0 38. 6 1.9 59.5

EXAMPLE 12 hydroxyethyl ammonium chloride, the formula for which Same as in Example 7 with the exception that the products of Examples 8 through 11 are evaluated as antistatic agents. The results are given in Table IV.

TABLE IV Electrostatic locator reading Antistatic evaluation of quaternary ammonium compound of example Approx. pH of treating soln.

EXAMPLE 13 EXAMPLES 1419 Examples 1 through 6 are repeated exactly with the ex ception that the specified amount (see Table I) of concentrated (70%) aqueous nitric acid is added to the solvent solution of the gamma-stearamidopropyl dimethyl amine prior to the addition of the ethylene oxide thereto. When the resulting quaternary ammonium salt is evaluated for its antistatic efiiectiveness as described in Example 7, the ratings on the treated polyacrylonitrile cloth are of the same general order as those given in column 3 of Table II with respect to the evaluation of the quaternary ammonium salts of Examples 1 through 6.

instead of adding all of the nitric acid prior to the addition of the ethylene oxide as described above, one can add it to the reaction mass concurrently with the addition of the ethylene oxide; or part of the nitric acid may be added to the reaction mass prior to starting the addition of the ethylene oxide and the remainder during and/or after completing the ethylene oxide addition; or part of the nitric acid may be added concurrently with the addition of the ethylene oxide and the remainder after all of the ethylene oxide has been added.

EXAMPLE Two hundred and sixty-six (266) g. (0.852) mole of gamma-myristamidopropyl dimethyl amine is dissolved in 590 g. p-dioxane, and to the resulting solution is added 90.5 ml. (1.1 mole) of concentrated hydrochloric acid. in an autoclave containing the foregoing solution is passed ethylene oxide (40 g.; 0.9 mole), and the reaction is continued for 3 hours at 80 C. The p-dio-xane solvent is removed by distillation under reduced pressure. The product is gamma-myristamidopropyl dimethyl betal CHzCHaOH I under Example 7.

EXAMPLE 21 Example 20 is repeated exactly with the exception that instead of concentrated hydrochloric acid there is used an equivalent amount of concentrated phosphoric acid containing about 98% H PO thereby to obtain gammamyristamidopropyl dimethyi beta'-hydroxyethyl ammonium phosphate (dihydrogen phosphate). 7

Similarly one can make gamma-stearamidopropyl dimcthyl betahydroxyethyl ammonium phosphate by using an equivalent amount of igamma-stearamidopropyl dimethyl amine as a starting reactant in place of gammamyristamidopropyl diethyl amine.

EXAMPLE 22 To 460 g. acetonitrile in an autoclave is added 250 g. (1.1 mole) of caprylamidopropyl dimethyl amine, and to the resulting solution is added 90.5 ml. 1.1 mole) of concentrated hydrochloric acid. To this solution at 50 C. is then added 53 g. (1.2 mole) of ethylene oxide over a period of 3 hours. Thereafter the acetonitrile is removed under reduced pressure. A yield of about 350 g. of gamma-caprylamidopropyl dimethyl beta-hydroxyethyl ammonium chloride is obtained. It shows excellent antistatic characteristics when tested as described under Example 7.

In a similar manner the corresponding gammahydroxypropyl ammonium chloride can be obtained by using an equivalent amount of propylene oxide instead of ethylene oxide.

The corresponding sulfate salts of both the aforementioned beta-hydroxyethy1 and gamma-hydroxypropyl derivatives are obtained by using an equivalent amount of concentrated (about sulfuric acid in place of concentrated hydrochloric acid.

EXAMPLE 23 One hundred and eighty-six (186) grams (0.48 mole) of gamma-abietamidopropyl dimethyl amine is d-issoived in an equal weight of acetone, and to the resulting solution is added 40 ml. (0.48 mole) of concentrated hydrochloric acid. About 24 g. (0.54 mole) of ethylene oxide is passed into the resulting solution. The react-ion mass that results is ailowed to stand for about 16 hours at about 45 C. The resulting quaternary ammonium compound, garnma-abietamidopropyl dimethyl beta'-hydroxyethyl ammonium chloride, shows excellent antistatic characteristics when tested as described under Example 7.

The corresponding diethyl and dipropyl ammonium chlorides are prepared by using equivalent amounts of gamma-stearamidopropyl diethyl amine and gammastearamidopropyl dipropyl amine as starting reactants in place of gamma abietamidopropyl dimethyl amine.

The corresponding gamma-heptamidopropyl methyl ethyl beta'-hydroxyethyl ammonium chloride and lauramidopropyl ethyl propyl ammonium chloride are prepared by using equivalent amounts of heptarnidopropyl methyl ethyl amine and of lauramidopropyl ethyl propyl amine, respectively, as starting reactants instead of gamma-abietamidopropyl dimethyl amine.

It will be understood, of course, by those skilled in the art that my invention is not limited (other than as to the liquid reaction medium comprising the specified organic solvent or mixture of two or more of them) to the specific ingredients or to the specific conditions of reaction that have been given in the foregoing examples solely by way of illustration. Thus, there can be used any amine corresponding to the general formula III where R, R and R" have the same meanings as given hereinbefore with reference to Formula I. Any organic or inorganic acid can be used such, for example, as acids the anions of which correspond to those hereinbefore given as illustrative of anions represented by Y in Formula I. Alkylene oxides containing either 2 or 3 carbon atoms, specifically ethylene oxide and propylene oxide, can be employed. Approximately equal molar proportions of amine, alkylene oxide and acid can be used. Generally, it is advantageous to employ a slight excess of the alkylene oxide reactant, for example from 0.1 mole percent to mole percent in excess. An excess of the acid, particularly at the end of the reaction, so that the quaternary ammonium compound has a pH below about 6.5, e.g., about 4.5-6.0, also is usually advantageous. This is particularly true when the quaternary compound is to be used as an antistatic agent.

The quaternary compounds prepared in accordance with the method of this invention are suitable for direct use as, for example, antistatic agents; or they may be diluted with a wide variety of solvents for such use. The invention makes it possible to prepare antistatic agents containing very minor amounts of water for use where water creates problems in rendering materials antistatic. Examples of such uses of antistatic agents include the incorporation of an antistatic agent into a molding (moldable) composition comprising a thermoplastic or thermosetting resin or polymer, which is then shaped as by molding, extruding, calendering, etc., and where appreciable amounts of water normally cause or tend to cause blistering, discoloration, decomposition, etc.

I claim: 1. The method of preparing a quaternary ammonium compound represented by the formula RI R-C ONHCH2C Hr-C HiN-R" wherein R is a member of the group consisting of aliphatic and alicyclic radicals containing at least 7 carbon atoms and up to about 20 carbon atoms, R and R are members of the group consisting of alkyl radicals having from 1 to 3 carbon atoms, inclusive, and monohydroxyalkyl radicals having from 2 to 3 carbon atoms, inclusive, R is a monohydroxyalkyl radical having from 2 to 3 carbon atoms, inclusive, and Y is the anion of an inorganic acid, said method comprising effecting reaction between (1) the corresponding amidopropylamine, (2) an alkylene oxide containing from 2 to 3 carbon atoms, inclusive, and (3) an acid the anion of which corresponds to Y in the above formula, said reaction being effected at a temperature ranging from about 35 C. up to the boiling temperature of the reaction mass and in a liquid reaction medium consisting essentially of at least one member selected from the group consisting of dioxane, ethylene glycol, ethylene glycol monoethyl ether, acetonitrile, acetone and chloroform.

2. A method as in claim 1 wherein R represents a heptadecyl radical, R and R each represent a methyl radical, R represents a beta'-hydroxyethyl radical, and the alkylene oxide is ethylene oxide.

3. A method as in claim, 1 wherein R represents a heptadecyl radical, R and R" each represent a methyl radical, R' represents a beta'-hydroxyethyl radical, Y represents a nitrate anion, the amidopropylamine is gamma-stearamidopropyl dimethyl amine, the alkylene oxide is ethylene oxide and the acid is nitric acid.

4. A method as in claim 1 wherein at least part of the acid is incorporated in the reaction mass not later than concurrently with the completion of the addition of all of the alkylene oxide to the reaction mass.

5. A method as in claim 1 wherein all of the acid is added to the reaction mass prior to the completion of the addition of all of the alkylene oxide to the reaction mass.

6. A method as in claim 1 wherein all of the acid is added to the admixture of solvent and amidopropylamine prior to starting the addition of the alkylene oxide to the reaction mass.

7. A method as in claim 1 wherein all of the acid is added to the reaction mass after completing the addition of all of the alkylene oxide to the reaction mass.

References Cited in the file of this patent UNITED STATES PATENTS 2,459,062 Cook et a1. Jan. 11, 1949 2,459,088 Moss et al. Jan. 11, 1949 2,589,674 Cook et al. Mar. 18, 1952 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,082,227 March 19, 1963 Allan E. Sherr It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 13, for "110 read poor column 6, line 38 for "dlethyl amine" read dimethyl amine Signed and sealed this 8th day of October 1963.

' (SEAL) Attest:

ER w SWIDER EDWIN L. REYNOLDS Attesting Officer Ac ting Commissioner of Patents 

1. THE METHOD OF PREPARING A QUATERNARY AMMONIUM COMPOUND REPRESENTED BY THE FORMULA 